Introduction

The M203 is a grenade launcher of US origin. It was designed in the late 1960's to replace the M79 in US service. The M203 is the first succesful under barrel grenade launcher and was designed to fit onto the M16A1. As a result the grenadier has a full size assault rifle as secondary weapon instead of relying on a pistol.

Design

The M203 is a breech loaded grenade launcher that uses the same ammunition as the M79 it was intended to replace. In order to load the M203 the barrel is moved forward and the round is inserted. The weapon is cocked and ready to fire when the barrel slides back in position. The M203 mounts on the M16A1 just in fromt of the magazine. The magazine also acts as a sort of pistol grip as the single action trigger assembly is located behind the barrel. The launcher is attached to the rifle by means of a wider square forearm with various holes for cooling. The flip up mechanical sight is fitted on top of the forearm. Unlike the original M203 later models are quick detachable and will fit to more types of rifles.

Firepower

The M203 is a single shot weapon that fires 40x46mm low velocity grenades. Besides the standard high explosive fragmentation rounds there is a wide selection of other rounds available. Due to the distance that the barrel slides forward upon reloading not all types of grenades can be loaded due to their length. An experienced operator can fire 5 to 7 rounds per minute. The effective range against point targets is 150 m. Area targets can be engaged out to 400 m.

Users

The fist user of the M203 was the US military and it was used during the later stages of the Vietnam war and all subsequent conflicts. At first the M203 was only used by operators of the M16 series of assault rifles. Since the M203 became available in versions that will mount on other types of weapons its use expanded even further. The M203 is common in North and South America, Asia and Africa.

M203

The original version of the M203 was designed to fit onto the M16A1 assault rifle. It is also used with the improved M16A2 series. It is attached to the rifle by removing the original handguard and replacing it with a much larger square one to which the launcher is attached.

M203A1

The M203A1 is a variant of the original M203 for use on the M4 Carbine. As the M203 has a much shorter handguard the original M203 will not fit. Mechanically the M203A1 is similar to the original M203, only the mount differs. The M203A1 replaces the lower part of the hand guard and will only fit on M4 carbines with a step cut barrel. The M203A1 is normally used with a shorter barrel to better suit the length of the M4. The original full length barrel is also available.

M203PI

The M203PI is a modification version of the original M203. It was developed as a private venture by R/M equipment in the late 1980's. The M203PI does not replace any handguard but uses a mounting bar. Early versions had the full length barrel, later versions the shorter barrel as used on the M203A1. It is also possible to mount a gripstock with pistol grip and shoulder stock for stand alone use.